Hydrokinetic torque converter

ABSTRACT

The rotary housing of a hydrokinetic torque converter, which can be utilized in the power train of a motor vehicle—for example, in conjunction with a continuously variable transmission—contains a torque monitoring device which is installed in such a way that it does not take up any, or any appreciable, additional space, especially in the axial direction of the housing. The torque monitoring device can serve to transmit torque between the lockup clutch and the output element of the torque converter. Additional features reside in the provision, configuration and manner of mounting of an auxiliary mass, and in the provision of a member for centering the piston of the lockup clutch in the housing as well as a member for centering the housing on the output element of a prime mover.

This is a division of application Ser. No. 09/082,285 filed May 20,1998, now U.S. Pat. No. 6,026,941. Each of these prior applications ishereby incorporated herein by reference, in its entirety.

BACKGROUND OF THE INVENTION

The invention relates to improvements in torque transmitting systems ingeneral, and more particularly to improvements in so-called hydrodynamicor hydrokinetic torque converters.

A hydrokinetic torque converter which can be modified and improved toembody the present invention is disclosed, for example, in publishedGerman patent application No. 44 20 959 A1. A torque converter of thetype disclosed in this published German patent application comprises arotary housing which can be driven by the output element of a primemover (such as a crankshaft or a camshaft of an internal combustionengine in the power train of a motor vehicle), a pump which is mountedin and is driven by the housing, a turbine which is rotatably mounted inthe housing and can transmit torque to a coaxial output element of thetorque converter, an optional stator which can be installed in thehousing between the pump and the turbine, and a so-called lockup orbypass clutch which can be engaged to transmit torque from the housingdirectly to the output element.

Torque converters of the above outlined character are frequentlycombined with a hydraulic or hydromechanical torque sensing ormonitoring device (hereinafter called torque sensor or sensor for short)which is normally designed to establish in a hydraulic supply conduit afluid pressure proportional to the magnitude of transmitted torque. Suchsensors are normally or often employed in conjunction with hydrokinetictorque converters which are designed to transmit torque from a primemover to a continuously variable transmission (CVT). A torque sensorwhich is employed in conjunction with a hydrokinetic torque converterfor controlled transmission of torque to a continuously variabletransmission serves to ensure that one or more force transmitting partsare automatically acted upon with a pressure which is a function of thetorque to be transmitted by the transmission.

A continuously variable transmission with two adjustable sheaves orpulleys and an endless flexible torque transmitting element (such as achain or a belt) trained over the pulleys is disclosed, for example, inpublished German patent application No. 42 34 294 A1. A torque sensor isassociated with at least one of the adjustable pulleys in order toensure that the arcuate portion of the endless flexible element which istrained over the at least one pulley is clamped with a force which isproportional to the magnitude of the torque to be transmitted by therespective pulley. For example, the torque sensor can comprisepreferably spherical rolling elements cooperating with surfaces arrangedto transmit clamping and/or other forces related to the ratio of and tothe torque to be transmitted by the torque converter.

As a rule, a torque sensor is installed next to the housing of ahydrokinetic torque converter, for example, between the torque converterand a continuously variable transmission. Reference may be had, forexample, to pages 181-196 of the 1990 edition of German “VDI-Berichte”(meaning: Reports by the Association of German Engineers). A drawback ofsuch mounting of a torque sensor is that, though it is or can be madereadily accessible, it contributes significantly to the bulk of thepower train, especially as considered in the axial direction of thetorque converter.

Reference may also be had to commonly owned U.S. Pat. No. 5,667,448granted Sep. 16, 1997 to Oswald Friedmann for “POWER TRAIN”. Thepatented power train employs a torque sensor which is installed betweentwo torque transmitting systems in the form of clutches and anadjustable pulley of a continuously variable transmission. That clutchwhich is at least partially engaged receives torque from the outputshaft of a prime mover, e.g., an internal combustion engine in the powertrain of a motor vehicle. In a motor vehicle wherein the space under thehood is at a premium, the placing of a torque sensor as a discrete partbetween neighboring constituents of the power train is likely toincrease the overall axial length of the power train to an extent whichrenders the power train unsuitable for use in certain types of motorvehicles.

U.S. Pat. No. 4,577,737 (granted Mar. 25, 1986 to Niikura et al. forLOCK-UP TORQUE CONVERTER AND METHOD FOR CONTROLLING CLUTCH SLIP INLOCK-UP TORQUE CONVERTER) discloses a hydrokinetic torque converter witha lockup clutch and an electromagnetic torque sensor which is surroundedby the pump as well as by the turbine of the torque converter and isinstalled radially outwardly of the radially inner portion of the pistonof the lockup clutch. Such distribution of the pump, turbine, lockupclutch and torque sensor in the housing of the torque convertercontributes significantly to the space requirements of the torqueconverter, particularly in the radial direction of the housing.

OBJECTS OF THE INVENTION

An object of the invention is to provide a novel power train which canbe utilized, for example, in a motor vehicle and embodies an improvedcombination of a torque converter with a torque sensing or monitoringdevice (sensor or torque sensor).

Another object of the invention is to provide a simple, compact andreliable combination of a hydrokinetic torque converter and an automatictorque sensor.

A further object of the invention is to provide a hydrokinetic torqueconverter which embodies a torque sensor.

An additional object of the invention is to provide a novel and improvedcombination of a hydrokinetic torque converter, which embodies a torquesensor, with a prime mover, such as the internal combustion engine of amotor vehicle.

Still another object of the invention is to provide a hydrokinetictorque converter which embodies a torque sensor and is constructed andassembled in such a way that its space requirements (as considered inthe axial direction of its constituents) need not exceed the spacerequirements of a standard torque converter which does not embody atorque sensor.

A further object of the invention is to provide a novel and improvedmethod of increasing the combined mass of rotary parts of a torqueconverter which embodies a torque sensor.

Another object of the invention is to provide a novel and improvedtorque sensor which can be installed with advantage in the housing of ahydrokinetic torque converter but can be utilized also in many other(additional) ways and fields.

An additional object of the invention is to provide a torque sensorwhich constitutes an improvement over and a further development ofdevices disclosed in German patent application No. 195 44 644 A1.

Still another object of the invention is to provide a novel and improvedtwin-chamber torque sensor.

A further object of the invention is to provide a motor vehicle whichembodies a hydrokinetic torque converter and a torque sensor of theabove outlined character.

Another object of the invention is to provide a torque converter and atorque sensor which can employ a large number of simple and inexpensiveparts.

An additional object of the invention is to provide a novel method ofintegrating a torque sensor into a hydrokinetic torque converter.

Still another object of the invention is to provide a novel and improvedmethod of assembling the contents of the housing of a hydrokinetictorque converter in a manner which exhibits numerous importantadvantages as concerns the compactness, simplicity, useful life, initialand maintenance cost, and accessibility of the contents.

A further object of the invention is to provide a novel and improvedhousing for a hydrokinetic torque converter which embodies a so-calledlockup or bypass clutch and a torque sensor of the above outlinedcharacter.

Another object of the invention is to provide a novel and improvedlockup or bypass clutch for use in the above outlined hydrokinetictorque converter.

An additional object of the invention is to provide a novel and improvedcontinuously variable transmission which cooperates with or embodies oneor more hydrokinetic torque converters and torque sensors of the aboveoutlined character.

Still another object of the invention is to provide a hydrokinetictorque converter which can be utilized, for example, in the power trainsof motor vehicles as a superior substitute for presently known andutilized torque converters.

A further object of the invention is to provide the above outlinedhydrokinetic torque converter with novel and improved signal generatingmeans.

Another object of the invention is to provide a novel and improved modeof transmitting torque from the housing directly to the output elementof a hydrokinetic torque converter.

SUMMARY OF THE INVENTION

The invention is embodied in a hydrokinetic torque converter whichcomprises a housing adapted to rotate about a predetermined axis andincluding a driving section arranged to receive torque from an outputcomponent of a suitable prime mover, e.g., from a camshaft or acrankshaft of an internal combustion engine in the power train of amotor vehicle. The housing accommodates a rotary pump, a rotary turbineand an optional stator, and the torque converter further comprises anengageable and disengageable lockup clutch or bypass clutch (hereinaftercalled lockup clutch) which is provided in the housing and spacedlysurrounds the predetermined axis. Still further, the torque convertercomprises a torque sensing or monitoring device (hereinafter calledsensor or torque sensor) which, in accordance with a feature of theinvention, is disposed in the housing between the turbine and thedriving section, as seen in the direction of the predetermined axis, andradially inwardly of the lockup clutch.

The aforementioned output component of the prime mover can be said toconstitute a rotary input member of the torque converter and is(directly or indirectly) non-rotatably connected with the drivingsection of the housing.

The torque converter further comprises a rotary output elementpreferably including a shaft which is arranged to drive a transmission(i.e., which can constitute a rotary input element of the transmission).The output element can further comprise a tubular hub whichnon-rotatably surrounds the shaft and is arranged to receive torque fromthe driving section of the housing by way of the turbine or directly byway of the lockup clutch. The transmission is or can constitute acontinuously variable transmission (CVT).

The lockup clutch preferably comprises a piston which is mounted on theoutput element of the torque converter in such a way that it can moverelative to the output element (e.g., relative to the aforementionedhub) in the direction of the predetermined axis but cannot rotaterelative to the output element. A friction surface of the drivingsection of the housing is in (direct or indirect) frictional torquetransmitting engagement with a friction surface of the piston in theengaged condition of the lockup clutch, and the driving section isrotatable relative to the piston in the disengaged condition of theclutch.

If the rotary output member of the prime mover is not directly connectedto the driving section of the housing, the indirect connection betweensuch parts can include a flexible plate-like torque transmitting memberwhich is interposed between and is non-rotatably connected with theoutput member as well as with the driving section. As already mentionedabove, the output member of the prime mover can constitute a camshaft ora crankshaft of an internal combustion engine.

The flexible torque transmitting member may but need not be directlyconnected with the driving section of the housing of the torqueconverter. In accordance with a presently preferred embodiment of theinvention, the indirect connection between the flexible member and thedriving section can include an annular plate-like connector and meansfor separably securing the connector to the flexible torque transmittingmember.

The torque converter can further comprise an auxiliary mass which isaffixed to the driving section of the housing and/or to the flexibletorque transmitting member and/or to the annular plate-like connectorand is located at that side of the driving section which faces away fromthe clutch, namely toward the output member of the prime mover. Forexample, the auxiliary mass can be affixed to the flexible torquetransmitting member by bolts and nuts, screws and/or other types ofthreaded fasteners extending through openings provided for the fastenersin the flexible torque transmitting member and/or in the connector. Theauxiliary mass can include or constitute a casting.

The connector and the flexible torque transmitting member can bedesigned and mounted to define an annular space for an auxiliary mass.The latter can be provided with an annulus of signal generatingrecesses, for example, in that (outer) side of the auxiliary mass whichfaces away from the axis of the rotary housing. Alternatively, theauxiliary mass can constitute an annulus having a circumferentialsurface provided with a groove (such as a circumferentially completegroove), and the signal generating means (e.g., for generating signalswhich can be processed to denote the RPM and/or certain angularpositions of the auxiliary mass) then further comprises a shroud (e.g.,in the form of a washer or ring) surrounding the circumferential surfaceof the annular auxiliary mass and provided with signal generatingopenings in the form of windows in register with the adjacent portionsof the groove. The shroud can include or constitute a ring of metallicsheet material, and its windows can form an annular array in that theyare spaced apart from each other in a circumferential direction of theaforementioned surface of the auxiliary mass.

The flexible torque transmitting member of the means for connecting thedriven section of the housing to the output member of the prime movercan have a substantially circular outline, and the auxiliary mass can beprovided with a tubular portion defining a recess for the radially outermarginal portion of the flexible member. In other words, a portion ofthe auxiliary mass can surround the flexible member.

Alternatively, the flexible torque transmitting member can have apolygonal outline (e.g., that of a triangle, particularly an equilateraltriangle), i.e., the flexible member can be provided with severalcorners which are received in complementary recesses in that side of theauxiliary mass which faces away from the driving section of the housing.

A standard annular starter gear can be provided to surround and to beaffixed (e.g., welded) to the periphery of the flexible torquetransmitting member, of the connector or of the auxiliary mass. Forexample, the starter gear can be mounted on the aforementioned tubularportion of the mass, i.e., on that portion which surrounds the peripheryof the flexible torque transmitting member.

In lieu of consisting of or including a casting (or in addition to acasting), the auxiliary mass can consist (at least in part) of asuitable metallic sheet material, e.g., a ductile material which can bereadily shaped in a number of ways including several presently preferredprocedures. For example, the auxiliary mass can include or constitute anannulus and includes a radially inner portion as well as a radiallyouter portion which is affixed to the driving section of the housing.The radially inner portion of such auxiliary mass can include two layersextending substantially radially of the predetermined axis and overlyingeach other (as seen in the direction of such axis). The radially outerportion of such auxiliary mass can be of one piece with one of the twooverlying layers of the radially inner portion of the auxiliary mass.For example, the radially outer portion of the auxiliary mass and theone layer of the radially inner portion of such auxiliary mass can makean angle which is or at least approximates 90°.

Alternatively, an auxiliary mass which consists (at least in part) of ametallic sheet material can include a radially inner portion adjacentthe flexible torque transmitting member, and a radially outer portionincluding two interfitted tubular layers adjacent the driving section ofthe housing. One of the two layers is of one piece with and is inclined(e.g., at an angle of at least substantially 90°) relative to theradially inner portion of such auxiliary mass. The one layer issurrounded by the other layer of the radially outer portion of theauxiliary mass. The connector can include a tubular radially outerportion which extends in the direction of the predetermined axis towardthe driven section of the housing, and such tubular radially outerportion of the connector can include a first layer surrounding thelayers of the radially outer portion of the flexible torque transmittingmember as well as a second layer which surrounds the first layer of suchradially outer portion of the connector.

Such torque converter can further include externally threaded malefasteners which are affixed to a the connector and extend in substantialparallelism with the predetermined axis in a direction away from thedriving section of the housing and through openings provided for suchmale fasteners in the flexible torque transmitting member and in aradially extending substantially washer-like portion of a ring-shapedattachment, preferably an attachment having a radially extending annularportion and an axially extending annular portion making with theradially extending annular portion an angle of at least close to 90°.The radially extending portion of the attachment can be said toconstitute a washer which preferably overlies the flexible torquetransmitting member. The axially extending annular portion of suchattachment can be said to constitute a tube which at least partiallysurrounds the radially outer portion of the connector. Such torqueconverter preferably further comprises female fasteners (e.g., nuts)which mate with the male fasteners and are outwardly adjacent thewasher-like radially inner portion of the attachment to thus secure theattachment to the connector. Rivets can be utilized to secure thewasher-like radially inner portion of the attachment to the flexibletorque transmitting member of the means for transmitting torque from therotary output member of the prime mover to the driving section of thehousing of the improved torque converter. The tubular radially outerportion of the attachment can be provided with an annulus of signalgenerating windows.

In accordance with a further presently preferred embodiment, theauxiliary mass can be of one piece with the driving section of thehousing. For example, the auxiliary mass and the driving section of thehousing can constitute a one-piece metallic casting. The flexible torquetransmitting member can be secured to the auxiliary mass by malefastener means having externally threaded portions (such as the shanksof screws or bolts) extending into tapped bores of the casting includingthe auxiliary mass and the driving section of the housing.

The auxiliary mass which is of one piece with the driving section of thehousing of the torque converter can be provided with a recess at thatside which faces away from the turbine, and such recess can receive theradially outermost marginal portion of the flexible torque transmittingmember. Such flexible member can have a polygonal outline with severalcorners, and the aforementioned recess of the auxiliary mass can includeportions which snugly receive the corners of such polygonal flexibletorque transmitting member. The polygonal outline of such flexiblemember can be that of an equilateral triangle.

The driving section of the housing, and particularly that drivingsection which is of one piece with the auxiliary mass, can be of onepiece with a centrally located hub coaxial with the housing of thetorque converter and (directly or indirectly) connectable with therotary output member of the prime mover for the torque converter.

The housing of the torque converter further comprises a second sectionwhich is welded to or otherwise connected, with and hence rotated by thedriving section. The second section can be designed to rotate the pumpand rotatably surrounds the aforementoned output element of the torqueconverter. The piston of the lockup clutch is rotatable with the turbineand can include a conical radially outer portion which engages acomplementary second conical portion provided on (and preferably but notnecessarily forming part of) the driving section of the housing when thelockup clutch is engaged. The conical portions of the piston and of thedriving section confront each other, and the lockup clutch preferablyfurther comprises at least one friction lining which is affixed to oneof the conical portions and is engaged by the other conical portion inthe engaged condition of the lockup clutch. The piston is movable in thedirection of the predetermined axis toward and away from the drivingsection of the housing to respectively engage and disengage the lockupclutch, and the torque sensor can comprise neighboring profiled annularmembers in the form of discs having confronting ramps. Such torquesensor further comprises one or more spherical or otherwise configuratedspreading elements between the two profiled members to move one of theprofiled members axially and away from the other profiled member whenone of the profiled members is caused to turn relative to the otherprofiled member. The first profiled member of the torque sensor isarranged to rotate with the output element of the torque converter, andthe second profiled member is arranged to rotate with the piston aboutthe predetermined axis and to move relative to the piston in thedirection of such axis.

The just described piston of the lockup clutch can comprise a radiallyinner portion including a tubular flange which extends in the directionof the predetermined axis toward the driving section of the housing.Such torque converter can further comprise a first annular member whichis non-rotatably connected with the radially inner portion of the pistonand has a tubular radially inner portion provided with internal teeth, asecond annular member having external teeth mating with the internalteeth of the first annular member and a radially inner portion which isrotatable relative to the output element of the torque converter aboutthe predetermined axis and is movable relative to the output element inthe direction of the predetermined axis, and a third annular memberincluding a radially outer first tubular portion rotatable relative tothe tubular flange of the piston about the predetermined axis andmovable relative to the flange of the piston in the direction of thepredetermined axis. The third annular member further comprises aradially inner second tubular portion which is non-rotatably mounted onthe second annular member, and the second profiled annular member of thetorque sensor can include a radially outer portion provided withexternal teeth in mesh with internal teeth provided on a second tubularportion of the third annular member. Such torque converter can furthercomprise an annular plunger which is non-rotatably provided on aradially inner portion of the second profiled annular member of thetorque sensor and includes a tubular first portion extending in thedirection of the predetermined axis toward the second section of thehousing, a second portion extending from the tubular first portionoutwardly toward the lockup clutch, and a tubular third portion whichextends from the second portion of the plunger toward the drivingsection of the housing and sealingly engages the tubular first portionof the third annular member. The third portion of the plunger isrotatable relative to the tubular first portion of the third annularmember about the predetermined axis and is movable relative to thetubular first portion of the third annular member in the direction ofthe predetermined axis.

The second portion of the plunger can extend radially or at leastsubstantially radially of the predetermined axis.

As mentioned above, the output element of the torque converter cancomprise a hub and a shaft which is non-rotatably surrounded by the hub.The first profiled annular member of the torque sensor can benon-rotatably secured to the hub, the second profiled annular member ofthe torque sensor can be mounted on the hub for rotation about thepredetermined axis in such a way that it can move relative to the hub inthe direction of such axis, and the tubular first portion of the plungercan be mounted in sealing engagement with an annular external collar ofthe hub so that it is rotatable about the collar (i.e., about thepredetermined axis) and is movable relative to the collar in thedirection of such axis. The radially inner portion of the second annularmember is rotatable on the hub about the predetermined axis and ismovable relative to the hub in the direction of such axis. The plunger,the collar, the hub and the second and third annular members jointlydefine a fluid-containing plenum chamber, and the hub comprises at leastone channel in communication with the plenum chamber for admission of afluid (such as oil) into and for evacuation of fluid from the chamber.

The second profiled annular member of the torque sensor, the plunger,the collar of the hub and another portion of the hub preferably define asecond fluid-containing plenum chamber, and the output element of thetorque converter then defines at least one second channel whichcommunicates with the second plenum chamber to permit admission of afluid into the second chamber or to permit the fluid to flow from thesecond chamber in actual use of the torque sensor.

The third annular member can further include a portion which extendssubstantially radially of the predetermined axis and includes a tubularpart sealingly engaging the hub. The tubular part is rotatable relativeto the hub about the predetermined axis and is movable relative to thehub in the direction of such axis.

In accordance with a modification, the first profiled annular member ofthe torque sensor is non-rotatably secured to the hub of the outputelement of the torque converter, the second profiled annular member ofthe torque sensor is rotatable on the hub about the pre-determined axisand is movable relative to the hub in the direction of such axis, andthe tubular first portion of the plunger is in sealing engagement withthe annular external collar of the hub and is rotatable on the collarabout the predetermined axis and movable relative to the collar in thedirection of such axis. The radially inner portion of the second annularmember is rotatable on the hub about the predetermined axis and ismovable relative to the hub in the direction of such axis. The secondprofiled annular member of the torque sensor, the plunger, the collar ofthe hub and another portion of the hub jointly define a fluid-containingplenum chamber, and the output element of the torque converter definesat least one channel which communicates with the plenum chamber. Thepiston, at least one of the three annular members, the plunger and/or atleast one section of the housing can be obtained by conversion ofsuitable sheet metal blanks in a deep drawing machine.

That (normally frustoconical) portion of the lockup clutch which is infrictional contact with the piston when the clutch is engaged need notalways be of one piece with the driving section of the housing. Thus,such portion of the lockup clutch can constitute a discrete torquetransmitting part which is non-rotatably affixed to the inner side ofthe driving section and is in frictional contact with the piston whenthe lockup clutch is at least partially engaged.

The driving section of the housing can include a wall which extends atleast substantially radially of the predetermined axis, and the discretetorque transmitting part of the lockup clutch can be welded or otherwiseaffixed to such radial wall of the driving section. Alternatively, thediscrete torque transmitting part can be affixed to a tubular wallforming part of the driving section and extending in the direction ofthe predetermined axis. For example, the discrete torque transmittingpart can be laser welded to the radial or tubular wall of the drivingsection. Alternatively, such part can be riveted to the driving section.

The improved torque converter can further comprise means for centeringthe piston of the lockup clutch on the output element of the torqueconverter in the disengaged condition of the clutch. The centering meanscan comprise a substantially sleeve-like bearing member which isnon-rotatably received in a central opening of the piston and surroundsthe output element of the torque converter. An internal surface of thebearing member can be provided with a cylindrical portion and a conicalportion, and the output element of such torque converter has an externalsurface including a cylindrical portion surrounded by the cylindricalportion of the internal surface of the bearing member and a conicalportion which is complementary to the conical portion of the internalsurface of the bearing member and abuts the conical portion of theinternal surface in the disengaged condition of the lockup clutch.

The bearing member can be a press fit in the central opening of thepiston of the lockup clutch, and a sealing device (such as an O-ring)can be interposed between the bearing member and the output element ofthe torque converter. For example, the bearing member can be providedwith an internal groove for such sealing device. Alternatively, thesealing device can be installed in an external groove of the outputelement of the torque converter. The construction of the means forcentering the piston in the disengaged condition of the lockup clutchcan be simplified if the radially inner portion of the piston isprovided with a conical internal surface complementary to a conicalexternal surface which is provided on the output element of the torqueconverter and abuts the conical internal surface of the piston in thedisengaged condition of the lockup clutch. The conical external surfaceof the output element can be provided with a circumferential groove fora sealing device which sealingly engages the conical internal surface ofthe radially inner portion of the piston in the disengaged condition ofthe lockup clutch.

The output element of the torque converter can be provided with adiscrete centering member having the aforementioned complementaryconical external surface, and at least a portion of such discretecentering member can consist of a suitable elastomeric material. Meanscan be provided to anchor the discrete centering member in the rotaryhub of the output element of the torque conveter; such anchoring meanscan comprise an annular groove provided in the hub or in the discretecentering member and a projection provided on the discrete centeringmember or on the hub and received in the groove.

One of the complementary conical surfaces can be provided with anannular groove for an annular sealing device (such as an O-ring) whichestablishes a seal between the complementary conical surfaces in thedisengaged condition of the lockup clutch.

An additional feature of the invention resides in the provision of noveland improved means for centering the driving section of the housing ofthe torque converter on the rotary output member of a prime mover. Suchcentering means can include the aforementioned flexible plate-liketorque transmitting member which is connectable with the output member,and an annular plate-like torque transmitting connector serving totransmit torque between the flexible member and the driving section ofthe housing. The radially outer portions of the flexible member and theconnector (namely those portions which are remote from the predeterminedaxis of the housing) can be non-rotatably affixed to each other bysuitable securing means. Such securing means can include threadedfasteners in the form of screws, bolts and nuts or the like.

The connector can be provided with a hub which is coaxial with thehousing of the torque converter and is received in a coaxial recess ofthe output member of the prime mover. Alternatively, the connector caninclude a centrally located centering section which surrounds acentrally located cylindrical external surface of the rotary outputmember of the prime mover. As already mentioned above, the output memberof the prime mover can constitute a camshaft or a crankshaft of aninternal combustion engine in the power train of a motor vehicle.

Still further, accurate centering of the driving section of the housingon the output member of the prime mover can be achieved by providing thedriving section of the housing with a centrally located centeringprojection which is journalled in the rotary output element of thetorque converter. Such centering projection may but need not be hollowand can extend in the direction of the predetermined axis toward theturbine in the internal compartment or space of the housing.

The connector can have a polygonal outline (such outline can at leastapproximate the outline of an equilateral triangle) and includes aplurality of corners which can be offset in the direction of thepredetermined axis toward the flexible torque transmitting member of themeans for centering the driving section of the housing on the outputmember of the prime mover. The flexible torque transmitting member ispreferably provided with recesses for such corners of the polygonalconnector. The connector can include portions which are bonded (e.g.,welded) to the flexible torque transmitting member of the centeringmeans.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved hydrokinetic torque converter itself, however, both as to itsconstruction and the mode of assembling and operating the same, togetherwith numerous additional features and advantages thereof, will be bestunderstood upon perusal of the following detailed description of certainpresently preferred specific embodiments with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partly schematic axial sectional view of a hydrokinetictorque converter with a lockup clutch and with a built-in torque sensorwhich embodies one form of the invention;

FIG. 2 is a fragmentary axial sectional view of a modified hydrokinetictorque converter with an auxiliary mass secured to the outer side of thedriving section of its housing;

FIG. 3 is a similar fragmentary axial sectional view of a firstmodification of the hydrokinetic torque converter shown in FIG. 2;

FIG. 4 is a similar fragmentary axial sectional view of a secondmodification of the hydrokinetic torque converter which is shown in FIG.2;

FIG. 5 is a similar fragmentary axial sectional view of a thirdmodification of the torque converter shown in FIG. 2;

FIG. 6a is a similar fragmentary axial sectional view of a fourthmodification of the torque converter shown in FIG. 2;

FIG. 6b is a smaller-scale elevational view of the torque converterembodying the structure of FIG. 6a as seen from the left-hand side ofFIG. 6a;

FIG. 7 is a fragmentary axial sectional view of a fifth modification ofthe torque converter which is shown in FIG. 2;

FIG. 8 is a similar fragmentary axial sectional view of a torqueconverter constituting a sixth modification of the torque converterwhich is illustrated in FIG. 2;

FIG. 9 is a similar fragmentary axial sectional view of a torqueconverter constituting a seventh modification of the torque converterwhich is illustrated in FIG. 2;

FIG. 10 is a fragmentary axial sectional view of a hydrokinetic torqueconverter departing from that shown in FIG. 1 in that it employs adifferent lockup or bypass clutch;

FIG. 11 is a fragmentary axial sectional view similar to that of FIG. 10but showing a portion of a third lockup clutch;

FIG. 12 is a fragmentary axial sectional view of a hydroknetic torqueconverter having novel and improved means for centering the piston ofthe lockup clutch in the disengaged condition of the clutch;

FIG. 13 is a fragmentary axial sectional view similar to that of FIG. 12but showing modified centering means for the piston of the lockupclutch;

FIG. 14 is a fragmentary axial sectional view similar to that of FIG. 12or 13 but showing a further centering means for the piston of the lockupclutch in the disengaged condition of such clutch.

FIG. 15 is a fragmentary axial sectional view of a hydrokinetic torqueconverter embodying a further centering means for the piston of thelockup clutch;

FIG. 16 is a fragmentary axial sectional view similar to that of FIG. 15but showing certain details of additional centering means for the pistonof the lockup clutch;

FIG. 17 is a fragmentary axial sectional view of a hydrokinetic torqueconverter and of a novel and improved means for centering the housing ofthe torque converter on the output element of a prime mover, such as theinternal combustion engine of a motor vehicle;

FIG. 18 is an elevational view of certain constituents of the centeringmeans for the housing of the torque converter, substantially as seenfrom the left-hand side of FIG. 17;

FIG. 19 is a fragmentary sectional view similar to that of FIG. 17 butshowing modified means for centering the housing of the torque converteron the output element of a prime mover;

FIG. 20 is an elevational view of certain constituents of the modifiedcentering means substantially as seen from the left-hand side of FIG.19;

FIG. 21 is a fragmentary axial sectional view similar to that of FIG. 17or 19 but showing a third embodiment of the means for centering thehousing of the torque converter on the output element of a prime mover;and

FIG. 22 is an enlarged fragmentary axial sectional view of a modifiedpart of a centering means for the housing of the torque converter.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, there is shown a hydrokinetic or hydrodynamictorque converter 1 which comprises a composite housing 2 adapted to berotated about a predetermined axis X—X by the rotary output member 3 ofa prime mover (e.g., by the camshaft or crankshaft of an internalcombustion engine or an analogous prime mover in the power train of amotor vehicle). The output member 3 of the prime mover is the inputelement of the torque converter 1.

The housing 2 comprises a cupped driving section 4 which receives torquefrom the output member 3 of the prime mover, and a second cupped section5 which is rigidly and sealingly secured to the adjacent cylindrical endportion 4 a of the driving section 4 by a circumferentially extendingwelded seam 6. The open left-hand end portion of the second section 5 isreceived in the cylindrical open end portion 4 a of the driving section4.

The housing 2 confines a pump 7 having a set of vanes or blades 8 whichare or which can be directly affixed to (and can be of one piece with)the second section 5. The housing 2 also confines a turbine 10 which isrotatable with and relative to the pump 7 and is installed between thesubstantially radially extending left-hand wall of the driving section 4and the pump (as viewed in the direction of the axis X—X). An optionalstator 12 is normally provided in the housing 2 between the radiallyinner portions of the pump 7 and the turbine 10, again as viewed in thedirection of the common axis X—X of the parts 2, 3, 7, 10 and 12.

The turbine 10 is non-rotatably mounted on a sleeve-like hub 11 of arotary output element further comprising a shaft 9 which is surroundedby and receives torque from the hub 11. The shaft 9 can constitute aninput element of a transmission, such as a continuously variabletransmission (CVT) of the type disclosed, for example, in commonly ownedU.S. Pat. No. 5,711,730 granted Jan. 27, 1998 to Friedmann et al. for“TORQUE MONITORING APPARATUS”. The torque transmitting connectionbetween the hub 11 and the shaft 9 comprises internal teeth provided inthe hub 11 and mating with complementary external teeth 9′ of the shaft9.

The second section 5 of the housing 2 has a radially inner portion 13 inthe form of a cylinder or sleeve which extends into and is sealinglymounted in the housing or case of a transmission, such as theaforementioned patented CVT of Friedmann et al.

In addition to the pump 7, turbine 10 and stator 12, the internal spaceor compartment 14 of the housing 2 further accommodates an engageableand disengageable lockup clutch or bypass clutch 15 (hereinafter calledlockup clutch) which can be operated to transmit torque directly fromthe driving section 4 of the housing 2 to the hub 11 of the compositeoutput element including the parts 9, 9′ and 11. Still further, theinternal space 14 of the housing 2 accommodates a torque monitoringdevice or torque sensor 41.

That radially outer portion 21 of the driving section 4 which isimmediately adjacent to the cylindrical radially outermost portion 4 ahas a conical (and more specifically a frustoconical) shape and formspart of the lockup clutch 15. The tip of the imaginary cone includingthe conical portion 21 of the driving section 4 of the housing 2 islocated on the axis X—X to the left of the housing 2, as viewed in FIG.1.

The conical portion 21 can be replaced with a portion extending radiallyor substantially radially of the axis X—X (i.e., such modified versionof the conical portion 21 can be located in a plane which is normal tothe axis X—X) in response to an appropriate change of the configurationof the radially outermost portion 23 of an axially reciprocable piston17 of the lockup clutch 15. The inclination of the conical portion 23 ofthe illustrated piston 17 matches the inclination of the conical portion21 of the driving section 4 of the housing 2.

The lockup clutch 15 is at least partially engaged when the confrontingfriction surfaces of the conical portions 21, 23 engage each other withor withot slip. The clutch 15 is disengaged when the piston 17 is causedto move axially and away from the portion 21 of the driving section 4.

FIG. 1 further shows a friction lining 22 which can be affixed to theconical portion 23 of the piston 17 or to the conical portion 21 of thedriving section 4. It is also possible to operate without a frictionlining 22 or to provide a discrete friction lining on each of theconical portions 21, 23.

The piston 17 of the lockup clutch 15 and/or the driving section 4and/or the second section 5 of the housing 2 can be made of a suitablemetallic sheet material in any suitable way, for example, by resortingto a deep drawing technique.

A first annular member 32 (e.g., a sheet metal part shaped in a deepdrawing machine) is secured (such as riveted as actually shown inFIG. 1) to a radially inner portion of the piston 17. The radially innerportion 33 of the first annular member 32 is a relatively short cylinderor tube having an annulus of internal teeth 34 which mate with anannulus of complementary external teeth 35 provided on a radiallyoutermost portion of a second annular member 36. The latter has arelatively short cylindrical (tubular) radially inner portion or flange37 which is axially movably mounted on and surrounds the hub 11 of thecomposite output element 9, 9′, 11 of the torque converter 1. The secondannular member 36 can also be made of a metallic sheet material,particularly in a deep drawing machine of any known design. In order toensure an optimal subdivision and an optimal utilization of the space 14which is surrounded by the housing 2, the second annular member 36 caninclude a frustoconical portion 39 extending from the external teeth 35in a direction to the right, as viewed in FIG. 1 (i.e., toward theradially inner portion of the housing section 5). The frustoconicalportion 39, in turn, merges into a washer-like radially inner portion 40which carries the aforementioned flange 37 surrounding the hub 11. Theannular space between the radially inner portion of the driving section4 and the second annular member 36 accommodates the torque sensor 41.

A third annular member 42 (this member can also constitute a converted(deep drawn) blank of metallic sheet material) is installed in thehousing 2 at that side of the second annular member 36 which confrontsthe driving section 4. The connection between the annular members 36, 42can comprise a set of rivets (as actually shown in FIG. 1) or any othersuitable fasteners. The third annular member 42 comprises a firsttubular (cylindrical) portion 43 extending in the direction of the axisX—X and located radially inwardly of a larger-diameter second tubular(cylindrical) portion 44 having an annulus of internal teeth 44′. Thesecond portion 44 merges into a larger-diameter third tubular(cylindrical) portion 46 which constitutes a flange surrounded by acylindrical flange 47 constituting the radially innermost portion of thepiston 17. The flange 47 is movable relative to the flange 46 in thedirection of the axis X—X.

The radially innermost portion of the third annular member 42constitutes a relatively short cylindrical sleeve 48 which surrounds andis movable relative to the hub 11 in the direction of the axis X—X.Sealing elements (such as O-rings) 49 and 50 are interposed between theexternal surface of the hub 11 on the one hand, and the internalsurfaces of the flanges 37 and 48 on the other hand. A further sealingelement 51 (such as an O-ring) is installed between the flange 46 of thethird annular member 42 and the flange 47 of the piston 17.

The torque sensor 41 serves to generate a fluid pressure which is afunction of one or more parameters, particularly or at least a functionof the magnitude of the torque being transmitted by the lockup clutch 15when the latter is engaged (at least in part) to transmit torquedirectly between the output member 3 of the prime mover (i.e., betweenthe driving section 4 of the housing 2) and the output element 9, 9′, 11of the torque converter 1, namely when the transmission of torque doesnot take place (or does not take place exclusively) by way of thehousing 2, pump 7 and turbine 10.

The illustrated torque sensor 41 constitutes a hydromechanical torquetransmitting device and comprises two confronting profiled disc-shapedmembers 55, 56 located in that portion of the internal space orcompartment 14 which is disposed radially inwardly of the piston 17 ofthe lockup clutch 15 and between the central portion of the drivingsection 4 and the turbine 10 (as seen in the direction of the axis X—X).The confronting surfaces of the profiled disc-shaped members 55, 56(hereinafter called discs or profiled discs) constitute ramps and are inabutment with one or more rolling elements 57 (such as spheres) of thetorque sensor 41. The radially inner portion of the profiled disc 55 isrigidly secured to the hub 11, e.g., by welding (shown at 38). Theradially inner portion of the other profiled disc 56 is provided with ashort axially extending collar 54 which axially movably surrounds thehub 11. The radially outermost portion of the profiled disc 56 isprovided with an annulus of external teeth 58 which mate with theinternal teeth 44′ of the second tubular portion 44 of the third annularmember 42 in such a way that the disc 56 is movable relative to themember 42 in the direction of the axis X—X.

That side of the profiled disc 55 which faces toward the central portionof the second section 5 of the housing 2 is connected with a piston orplunger 59 (hereinafter called plunger to distinguish from the piston 17of the lockup clutch 15). The connection 53 between the plunger 59 andthe profiled disc 56 can constitute a welded joint.

The plunger 59 comprises a cylindrical (tubular) portion 60 whichextends axially from the profiled disc 56 toward the housing section 5so that its inner side (confronting the axis X—X) is slidable along theperipheral surface 61 of a radially outwardly extending collar 52 of thehub 11. A second portion 62 of the plunger 59 extends radially outwardlyfrom the portion 60 and merges into a second cylindrical (tubular)portion 63 having a cylindrical outer side in sliding engagement withthe internal surface of the tubular portion 43 of the third annularmember 42. The portion 63 of the plunger 59 extends from the radialportion 62 toward the central portion of the driving section 4.

A sealing element (such as an O-ring) 65 is provided between the portion60 of the plunger 59 and the peripheral surface of the collar 52 of thehub 11, and a further sealing element (e.g., an O-ring) 64 is installedbetween the portion 43 of the annular member 42 and the portion 63 ofthe plunger 59.

Each of the profiled discs 55, 56 and the plunger 59 can be made of asheet metal blank which is converted in a deep drawing machine.

FIG. 1 shows quite clearly that, due to its design and the mounting ofits constituents, the entire torque sensor 41 can be readily integratedinto the torque converter 1; more specifically, the sensor 41 can bereadily installed in that portion of the space 14 which is locatedradially inwardly of the lockup clutch 15 and axially between theturbine 10 and the driving section 4 of the housing 2. This renders itpossible to confine the sensor 41 in the interior of the housing 2without necessitating any, or any appreciable, increase in thedimensions of the torque converter, either radially of the axis X—X orin the direction of such axis. The parts which can be said to constituteimportant contributors to the aforedescribed dimensions and constructionof the, torque sensor 41 are the piston 17 of the lockup clutch and theaforementioned annular members 36 and 42.

The mode of operation of the torque converter 1 is as follows:

It is assumed that the lockup clutch 15 is engaged, i.e., that thefriction lining 22 rotates with one of the conical portions 21, 23 andbears against the other of these conical portions so that the clutch 15can transmit torque from the output member 3 and driving section 4 tothe hub 11 of the output element of the torque converter 1, i.e., to theshaft 9 which transmits torque to the transmission (such as a CVT) ofthe power train in a motor vehicle. More specifically, the torque isbeing transmitted from the friction surface of the conical portion 21 ofthe driving section 4, via friction lining 22 and the conical portion 23of the piston 17 which (by way of the mating teeth 34 and 35) transmitstorque to the annular member 36. The latter transmits torque to theannular member 42 as well as to the hub 11. The portion 43 of theannular member 42 rotates the profiled disc 56 of the torque sensor 41by way of the mating teeth 44′ and 58.

If the thus transmitted torque develops an abrupt rise or surge, theprofiled disc 56 is caused to turn relative to the profiled disc 55 ofthe torque sensor 41. As already mentioned above, the confrontingsurfaces of the discs 55, 56 are provided with suitably configuratedramps (not referenced in FIG. 1) which cause the rolling spreadingelement(s) 57 to move the disc 56 axially of the housing 2 and away fromthe disc 55 as soon as the disc 56 is caused to turn relative to thedisc 55. The axial movement of the disc 56 toward the center of thesecond housing section 5 is shared by the plunger 59. The new axialposition of (a portion of) the disc 56 is shown by dot-dash lines, as atI, and the new axial position of (a portion of) the plunger 59 is alsoshown by dot-dash lines, as at II.

The just discussed axial shifting of the disc 56 and plunger 59 entailsa reduction of the volume of a first plenum chamber 59A between theplunger 59, annular member 42 and hub 11. Some of the fluid (such asoil) which fills the plenum chamber 59A is caused to escape through achannel 70, which is provided in the hub 11, and for example into aplenum chamber of means for changing the axial position of one flange inone pulley or sheave of a continuously variable transmission (CVT),e.g., a transmission of the type disclosed in the aforementioned '730patent to Friedmann et al.

When the lockup clutch 15 is disengaged, i.e., when the conical portion23 of the piston 17 does not receive torque from the conical portion 21of the driving section 4, the housing 2 rotates the output element 9,9′, 11 of the torque converter 1 by way of the vanes 8 of the pump 7, afluid stream between the pump 7 and the turbine 10, and the turbine.

It is often preferred to design the torque sensor 41 in such a way thatit comprises the plenum chamber 59A as well as a second plenum chamber59B. The latter is defined by the plunger 59, the collar 52, anadditional portion of the hub 11 and the profiled disc 56. This secondplenum chamber 59B can receive and discharge fluid by way of at leastone channel 71 of the hub 11 of the torque converter 1. Pressurizedfluid which is expelled from the second chamber 59B via channel 71 canbe admitted into the aforementioned chamber of a means for effectingaxial movements of one flange of an adjustable pulley or sheave in acontinuously variable transmission.

The means for transmitting torque from the rotary output member 3 of theprime mover to the driving section 4 of the housing 2 comprises anannular plate-like flexible torque transmitting member 81 (known asflexplate) having a radially inner portion non-rotatably connected tothe output member 3, and an annular plate-like connector 85. The latterhas a radially inner portion which is welded (as at 80) and/or otherwisenon-rotatably secured to the driving section 4, and a radially outerportion which is secured to the flexible plate-like member 81 by bolts79 and/or other threaded fasteners (or in any other suitable way, e.g.,by rivets and/or by welding).

A customary starter gear 90 is mounted on and surrounds a radiallyoutermost tubular portion of the flexible member 81.

In accordance with another feature of the invention, the torqueconverter 1 can be equipped with an annular auxiliary mass (one shown at93 in FIG. 2) which can be designed to take up space which is availablebetween the outer side of the driving section 4 of the housing 2 and theconnector 85 of the means for transmitting torque from the output member3 of the prime mover to the housing 2. The auxiliary mass 93 is furtherprovided with signal generating means in the form of one or morerecesses 94 in the peripheral surface of the auxiliary mass. Such signalgenerating means can cooperate with a device which monitors the RPM ofthe prime mover.

The dimensions and the location of the auxiliary mass are preferablysuch that this mass can contribute to the primary mass of the rotaryparts of the torque converter 1 without necessitating any increase inthe radial and/or axial dimensions of the torque converter.

The auxiliary mass 93 of FIG. 2 is fitted into the available annularspace at the outer side of the conical portion 21 of the driving housingsection 4.

The flexible member 81 in the torque converter of FIG. 2 is a washerhaving a radially inner portion which is affixed to the output member 3of the prime mover by bolts and nuts 82 and/or other threaded (or othersuitable) fasteners. The radially outer portion of the flexible member81 has openings 83 in the form of bores for portions of threadedfasteners 84 which extend through registering openings of the annularconnector 85 and into tapped bores of the auxiliary mass 93. Theradially inner portion of the annular connector 85 is secured (e.g.,welded, as at 80) to the outer side of the housing section 4, and theradially outermost portion 92 of the connector 85 constitutes a shorttube or cylinder which surrounds the adjacent radially outermost portionof the flexible member 81 and is surrounded by and affixed to thestarter gear 90.

As can be seen in FIG. 2, the configuration of the auxiliary mass 93 isor can be selected in such a way that it at least substantially fillsthe available annular space between the outer side of the conicalportion 21 of the housing section 4 and the confronting side of theconnector 85.

The auxiliary mass 93 of FIG. 2 can constitute a metallic casting. Thismass and the starter gear 90 are disposed at opposite sides of theradially extending main portion of the connector 85, i.e., the weight ofthe mass 93 can be said to balance the weight of the gear 90.

FIG. 3 shows a modified annular auxiliary mass 78 which is a convertedblank of metallic sheet material. This auxiliary mass 78 is affixed(e.g., welded, as at 91) to the outer side of the driving section 4 ofthe housing and is secured to the radially outer portion of the flexiblemember 81 by screws 84 and/or other suitable fasteners. In other words,the connector 85 of FIG. 2 is or can be omitted. The radially outermostportion 95 of the flexible torque transmitting member 81 constitutes ashort cylinder or tube which is surrounded by and affixed to a startergear 90.

The auxiliary mass 78 of FIG. 3 has a radially extending portion 96composed of two overlapping disc-shaped layers including an outer layer(adjacent the flexible member 81) which is of one piece with a singletubular (cylindrical) layer 97 extending toward the driving section 4.The layer 97 is provided with one or more signal generating recesses 98(such as windows or slots extending through the entire layer 97). Theouter layer of the radially extending portion 96 of the auxiliary mass78 has radially inwardly extending preferably arcuate projections 76(only one shown in FIG. 3) which are welded (at 91) to the adjacent wallof the driving section 4. The projections 76 can constitute non-deformedparts of that portion of a sheet metal blank which is converted into thetwin-layer portion 96 of the finished auxiliary mass 78.

The angle between the outer layer of the radially extending portion 96and the single layer of the tubular portion 97 of the auxiliary mass 78can equal or approximate 90°.

The connection (by means of threaded fasteners 82) between the radiallyinner portion of the flexible torque transmitting member 81 and theoutput member 3 of the prime mover can be the same as that describedwith reference to FIG. 2.

FIG. 4 shows a modified auxiliary mass 99 which constitutes a tubularradially outermost portion of the connector 85 and has one or moresignal generating openings 100. The starter gear 90 is mounted on theauxiliary mass 99. The radially extending connector 85 is separablyconnected with the radially outermost portion of the flexible torquetransmitting member 81 by bolts 84 and nuts 86, and its radially innerportion is welded (as at 91) to the outer side of the driving section 4of the housing. A set of discrete nuts 86 can be replaced with aone-piece or composite ring-shaped female fastener which mates with theshanks of the bolts 84 and can be said to constitute an auxiliary massprovided in addition to or in lieu of the connector portion 99. If theportion 99 is omitted, the signal generating openings (corresponding tothe openings 100 of FIG. 4) can be provided in the radially outerportion of the common ring-shaped female fastener (auxiliary mass) whichreplaces the nuts 86.

FIG. 5 shows a further modification of a torque converter having anauxiliary mass 105 (e.g., a casting resembling the auxiliary mass 93 ofFIG. 2) and a modified connector or second auxiliary mass 78 resemblingthe similarly referenced part in the torque converter of FIG. 3. In eachinstance, the single or composite auxiliary mass serves to increase themass moment of inertia at the primary side of the torque converter. Asin the embodiments of FIGS. 2-4, the composite auxiliary mass (78+105)occupies space which is available in the torque converter between theouter side of the driving section 4 and the flexible torque transmittingmember 81.

Referring more specifically to FIG. 5, the first or main auxiliary mass105 is welded to the conical portion 21 of the driving section 4 or issimply form-lockingly held between the two mutually inclined portions ofthe second auxiliary mass or connector 78 and the conical portion 21.The auxiliary mass 105 is or can constitute a metallic casting, and theconnector 78 can be made of sheet metal and includes a radiallyextending portion 96 with two overlapping layers as well as an axiallyextending tubular or cylindrical portion 97 of one piece with theleft-hand layer of the portion 96. The portion 97 is provided with oneor more signal generating openings 98 and the portion 96 is secured tothe radially outer portion of the flexible torque transmitting member 81by threaded fasteners 84. The prongs 90 at the radially innermost partof the radially extending portion 96 may be welded (at 91) and/orotherwise affixed to the driving section 4.

The starter gear 90 is affixed to and surrounds a tubular radiallyoutermost portion of the flexible member 81.

The configuration of the composite auxiliary mass 78+105 of FIG. 5 ispreferably such that it at least substantially fills the space betweenthe conical portion 21 of the driving section 4 and the radially outerportion of the flexible member 81.

One of the layers of the radial portion 96 of the mass or connector 78can be omitted.

FIGS. 6a and 6 b show a portion of a torque converter wherein theauxiliary mass 106 constitutes a further modification of the auxiliarymass 93 in the embodiment which is shown in FIG. 2. The auxiliary mass106 is an annular casting having a peripheral surface facing radiallyoutwardly and away from the axis of the housing including the drivingsection 4 and provided with a circumferentially complete groove 101.Such peripheral surface of the auxiliary mass 106 is surrounded by aringshaped shroud 102 consisting of sheet metal or the like and havingone or more openings or windows 103 communicating with the groove 101and constituting signal generating openings.

The auxiliary mass 106 is affixed to the radially outer portions of theflexible torque transmitting member 81 and the connector 85 by bolts 84or analogous fasteners having externally threaded shanks extendingthrough registering openings of the members 81, 85 and into tapped boresof the auxiliary mass 106.

The connector 85 is welded to the driving section 4 and can be rivetedto the auxiliary mass 106 in addition to or in lieu of the connectionwhich is established by the fasteners 84.

The auxiliary mass 106 has a tubular portion 108 extending in thedirection of the axis of the torque converter and away from the housingsection 4 to define a recess 111 which receives the radially outermostparts of the members 81 and 85.

As shown in FIG. 6b, the outline of the flexible member 81 can resemblethat of an equilateral triangle with three corners snugly received inthe adjacent portions of the recess 111 within the extension 108 of theauxiliary mass 106. The central portion of the triangular flexibletorque transmitting member 81 is affixed to the output member 3 of theprime mover by threaded fasteners 82.

Again, the configuration and the dimensions of the auxiliary mass arepreferably selected in such a way that the auxiliary mass at leastsubstantially fills the space between the conical portion 21 of thedriving section 4 and the radially outermost portions of the members 81,85.

The starter gear 90 is affixed to and surrounds the tubular extension108 of the auxiliary mass 106. In view of the triangular outlines of themembers 81 and 85, the extension 108 can be configurated in such a waythat it contributes significantly to the bulk and weight of theauxiliary mass 106. It is clear that the members 81 and 85 can assume apolygonal shape other than that of an equilateral triangle withoutnecessitating a pronounced reduction of the mass, bulk and weight of thetubular extension 108.

FIG. 6b shows that the members 81, 85 are connected with the auxiliarymass 106 by three equidistant fasteners 84 each extending throughaligned openings in a discrete corner portion of the flexible torquetransmitting member 81 and the corresponding corner portion of theconnector 85.

The flexible torque transmitting members of FIGS. 7 and 8 can alsoresemble equilateral triangles received in complementary recesses of therespective auxiliary masses 109 and 113. This renders it possible togreatly increase the bulk and weight of the auxiliary masses 109 and113.

The annular mass 109 in the torque converter of FIG. 7 is a castingwhich is welded (at 110) to the outer side of the housing section 4 andis separably secured to the radially outermost portion of the flexibletorque transmitting member 81 by threaded fasteners 84, e.g., by threefasteners 84 in a distribution similar or identical to that shown inFIG. 6b. The mass 109 fills or practically fills the annular spacebetween the conical portion 21 of the driving section 4 and the radiallyouter portion of the flexible torque transmitting member 81. Suchradially outer portion of the preferably triangular member 81 isreceived in a recess 112 defined by a tubular extension 111 of the mass109.

The welded joint 110 between the mass 109 and the driving section 4 ispreferably provided slightly radially inwardly of the conical portion21. Such welded joint can be used jointly with or it can be replaced byother suitable bonding or other connecting means (not shown).

The recess 111 can be a single recess in that side of the mass 109 whichfaces away from the driving section 4, or a combination of threediscrete triangular recesses, one for each of the three corners of atriangular flexible torque transmitting member 81.

The starter gear 90 is affixed to and surrounds the extension 112 of theauxiliary mass 109. As shown in FIG. 7, the extension 112 can beprovided with a peripheral groove or cutout for the radially innerportion of the starter gear 90.

FIG. 8 shows a portion of a torque converter wherein the auxiliary mass113 is of one piece with a radially extending wall 114 of the drivingsection 4. The parts 4, 113 constitute a metallic casting. Theconfiguration of the mass 113 resembles that of the mass 109 which isshown in FIG. 7. The central portion of the wall 114 is preferably ofone piece with a hub 115 which surrounds the spindle 11 or the shaft 9(not shown in FIG. 8) of the output element of the torque converter.

The means for securing the casting including the auxiliary mass 113 tothe radially outermost portion of the flexible torque transmittingmember 81 comprises threaded fasteners 84. Additional fasteners 82 areprovided to non-rotatably secure the radially inner portion of theflexible member 81 to the output member 3 of the prime mover. Theradially outermost portion of the flexible member 81 is received in arecess 116 which is provided in the left-hand end face of the auxiliarymass 113 and is surrounded by the starter year 90.

The flexible member 81 can have a polygonal shape, e.g., that of anequilateral triangle (as shown in FIG. 6b). The shape of the recess 116then conforms to the outline of the polygonal flexible member 71. Itwill be seen that the embodiment of FIG. 8 need not utilize a membercorresponding to the aforementioned connector 85.

FIG. 9 shows a portion of a torque converter wherein the auxiliary mass117 is made of a sheet metal blank and is confined in the annular spacebetween the connector 85 and the conical portion 21 of the drivingsection 4. The radially inner portion of the connector 85 is welded (at91) to the outer side of the driving section 4 radially inwardly of theconical portion 21. This connector is made of a suitable metallic sheetmaterial and includes a washer-like radially extending portion adjacenta radially extending portion or layer 118 of the auxiliary mass 117, anda twin-layer tubular portion 119 which overlies the outer layer 120 ofthe twin-layer tubular radially outer portion of the auxiliary mass 117.The inner layer 121 of the radially outer portion of the mass 117 is ofone piece with and makes an angle of preferably 90° with the radiallyextending layer 118 of the mass 117. The radially outer portion 119 ofthe connector 85 has two tubular layers the outer of which is shorterthan the inner layer, and the latter is surrounded by the axiallyextending tubular portion 124 of an annular attachment 122 furtherhaving a radially extending portion 123 outwardly adjacent the radiallyoutermost portion of the flexible torque transmitting member 81.

The radially extending portion 124 is coaxial with a relatively shortouter layer of the axially extending radially outer portion 119 of theconnector 125 and is provided with one or more signal generatingopenings 125. Such opening or openings is or are adjacent a starter gear90 which is affixed to and surrounds the portion 124 of the attachment122.

Threaded fasteners 84′ have heads welded or soldered to the radiallyextending portion of the connector 85, and externally threaded shanksextending through registering openings provided in the radiallyoutermost portion of the flexible member 81 as well as through openingsin the radially extending portion 123 of the attachment 122. Such shanksmate with nuts (not shown) at the outer side of the portion 123 toestablish a fixed connection between the driving section 4, connector85, flexible member 81 and attachment 122.

The relatively short outer tubular layer of the axially extendingradially outermost portion 119 of the connector 85 reinforces the innertubular layer and can but need not abut the tubular portion 124 of theattachment 122. The tubular radially outer portions 119 and 124 can besaid to contribute to the bulk and weight of the auxiliary mass 117.

The fasteners 84′ can be omitted if the attachment 122 is riveted orbonded (e.g., welded) to the connector 85.

FIGS. 10 and 11 show that the axially fixed conical section (see thesection 21 in FIGS. 1-6a and 7-9) need not always be of one piece withthe driving section 4 of the housing of the improved torque converter.In FIG. 10, the conical portion 21 is replaced with a discrete hollowconical torque transmitting part 130 which is laser welded (at 138) tothe inner side of the radially extending wall of the driving section 4.The conical part 130 is in frictional engagement with a friction lining22 (which is assumed to be glued or otherwise secured to the conicalportion 23 of the piston 17) when the lockup clutch including the piston17 and the annular conical part 130 is engaged. The friction lining 22can be affixed to the discrete conical part 130, or each of the conicalportion 23 and conical part 130 can carry a discrete friction lining.

The provision of a discrete conical part 130 (which is ultimatelyaffixed to the housing section 4) contributes to lower cost of theclaimed torque transmitting assembly (torque converter) because thedriving section 4 of the corresponding housing is simpler than thepreviously described driving sections. The conical part 130 can be madein a deep drawing machine and can be provided with a continuous ordiscontinuous radial extension 131 which is of one piece with theconical constituent 132, i.e., with that portion of the part 130 whichcarries or is engageable with the friction lining. The laser weldedjoint 138 is provided between the radially extending portion 131 of theconical part 130 and the conical portion 132; such joint can be replacedwith another welded joint, with a set of rivets, or with any othersuitable connecting or affixing means.

The radially extending wall of the driving section 4 has a set ofsockets 134 which are tapped (at 133) to accept the threaded shanks offasteners (not shown) passing through a flexible member 81 (not shown inFIG. 10 or 11) and, if necessary, through a connector corresponding, forexample, to the part 85 shown in FIG. 9. The sockets 134 (only one shownis each of FIGS. 10 and 11) are suitably deformed and aftertreated(tapped) portions of the radially extending wall of the driving section4.

The discrete part 130 is or can be provided with pressure equalizingports 136 to permit a fluid (such as oil) to flow between thecompartments at the opposite sides of the part 130.

The difference between the conical parts 130 of FIGS. 10 and 11 is thatthe portion 131 of the conical part 130 shown in FIG. 11 is a short tubewhich is welded (e.g., laser welded, as at 138) to the tubular radiallyoutermost portion 135 of the driving section 4.

An advantage of the torque converters which embody the structure of FIG.10 or 11 is that the welded joints 138 are rather remote from the lockupclutch (including the piston 17 and the conical portion 132 of theseparately produced part 130) so that a distortion of the conicalportion 132 as a result of bonding of the part 130 to the drivingsection 4 is rather unlikely. Furthermore, the welding (at 137) of thetubular wall 135 of the driving section 4 to the second section (5) ofthe housing (2) of the torque converter embodying the structure of FIG.10 or 11 is also less likely to entail a distortion of the constituents(17, 132) of the lockup clutch if the conical part 130 is a separatelyproduced constituent which is laser welded (at 138) to the radially oraxially extending portion of the driving section 4 of the housing.

Another advantage of the separately produced parts 130 shown in FIGS. 10and 11 is that a torque converter originally without a lockup clutch (ora torque converter originally furnished with a lockup clutch havingradially extending frictionally engageable torque transmitting parts)can be retrofitted with a lockup clutch of the type shown in FIGS. 10and 11.

An additional advantage of the structures shown in FIGS. 10 and 11 isthat the simplified driving section 4 need not be as stiff (as seen inthe circumferential direction of the housing) as a driving section ofone piece with a conical portion (21).

Still further, and since the part 130 is a separately producedcomponent, the lockup clutch of a torque converter embodying thestructure of FIG. 10 or 11 can be more readily (positively) cooled (suchas with oil) because the conical portion 132 of the part 130 is not ofone piece with the driving section of the housing. Thus, the ports 136between the portions 131, 132 of the separately produced part 130 renderit possible to cool the respective portion 132 at that side which facesaway from the conical portion 23 of the piston 17. The necessarypressure differential at the opposite sides of the portion 132 of theseparately produced part 130 is normally available so that the fluidcoolant is forced to flow through the ports 136 and to cool that side ofthe portion 132 which faces away from the portion 23 of the piston 17.

FIG. 12 illustrates one mode of accurately and reproducibly centeringthe piston 17 of the lockup clutch 15 in the disengaged condition of theclutch, i.e., when the piston is disengaged (and does not receivetorque) from the conical portion 21 of the driving section 4 of thehousing. The centering is effected by the hub 11 of the output elementof the torque converter, and more particularly by cooperating surfacesat the radially innermost portion of the piston 17 and at the exteriorof the hub 11.

In accordance with conventional proposals, the axially reciprocablepiston of a lockup clutch has a cylindrical internal surface surroundinga cylindrical external surface of the output element of the torqueconverter. The piston of such conventional lockup clutch can beadequately centered when its conical portion, such as the portion 23 ofthe piston 17 shown in FIG. 12, (directly or indirectly) engages thecomplementary conical portion (such as the portion 21 in FIG. 12) of thelockup clutch. However, the aforementioned cylindrical internal andexternal surfaces cannot ensure an adequate centering of the piston of aconventional lockup clutch when such clutch is disengaged. Inadequatecentering of the piston in the disengaged condition of the lockup clutchcan cause the piston to wobble and/or to perform other undesirable straymovements which can affect the predictability and accuracy of operationand can shorten the useful life of such conventional lockup clutch.

In accordance with a feature of the present invention, the piston 17 ofthe lockup clutch 15 is centered at its radially outer part (23) incooperation with the conical portion 21 of the driving section 4 whenthe lockup clutch is engaged, and the radially inner part of the piston17 is centered by the hub 11 when the lockup clutch is disengaged.

FIG. 12 shows that the central opening 160 of the piston 17 receives anannular bearing member 151 which is a press fit so that it cannot turnand/or otherwise move relative to the piston. It is clear that thebearing member 151 can be otherwise fixed (e.g., welded) in the centralopening 160 of the piston 17. The bearing member 151 has an internalsurface including a cylindrical portion 153 and a conical centeringportion 154. The adjacent portion of the hub 11 has an external surfaceincluding a cylindrical portion 152 which is surrounded by thecylindrical portion 153, and a conical centering portion 150complementary to and engaged by the conical portion 154 when the lockupclutch 15 is disengaged. The angle (β) of slope of the conical surfaceportions 150, 154 can be a relatively small acute angle. These conicalsurface portions diverge in a direction toward the second section 5 ofthe housing of the torque converter which is shown in FIG. 12. Thecylindrical surface portions 152, 153 are located between the conicalportions 150, 154 on the one hand, and the central portion of thedriving section 4 on the other hand.

The reference character 155 denotes a frustoconical clearance betweenthe friction lining 22 (which is shown as being affixed to the conicalportion 23 of the piston 17) and the conical portion 21 of the drivingsection 4 when the lockup clutch 15 is disengaged; at such time, theconical surface portions 150, 154 center the retracted piston 17 on thehub 11.

The cylindrical portion 152 of the external surface of the hub 11 has acircumferentially complete groove 156 for a sealing element 157 (e.g.,an O-ring) which sealingly engages the cylindrical portion 153 of theinternal surface of the bearing member 151.

The means for centering the piston 17 in the housing of the torqueconverter a portion of which is shown in FIG. 13 is analogous to thatshown in FIG. 12, and its parts are denoted by identical referencecharacters. The difference is that the external groove 156 of the hub 11(FIG. 12) is replaced with a circumferentially complete internal groove161 in the cylindrical portion 153 of the internal surface of thebearing member 151 and receives a sealing element 157 (e.g., an O-ring)which engages the cylindrical portion 152 of the external surface of thehub 11.

FIG. 13 further shows a radially outwardly extending collar 162 whichforms part of the bearing member 151 and abuts the adjacent side of theradially innermost portion (at the central opening 160) of the piston17. The collar 162 may but need not be positively secured (e.g., welded)to the piston 17.

FIG. 14 shows a portion of a torque converter wherein the means forcentering the piston 17 in the disengaged condition of the lockup clutch(see the clearance 155) comprises a frustoconical radially innermostportion 158 of the piston 17 and a complementary frustoconical centeringportion of the hub 11. The conical surface 150 of the centering portionof the hub 11 has a circumferentially complete groove 159 for a suitablesealing element 163 (e.g., an O-ring) which is sealingly engaged by theportion 158 of the piston 17 in the disengaged condition of the lockupclutch.

FIG. 15 shows that the conical portion 158′ of the piston 17 can extendradially inwardly and to the left, i.e., toward the central portion ofthe non-illustrated driving section of the housing in the lockup clutchwhich embodies the structure of FIG. 15.

FIG. 16 shows a ring-shaped discrete centering member 165 which is madeof an at least partially resilient (elastomeric) plastic material and isanchored in and surrounds a portion of the hub 11 to cooperate with theconical radially innermost portion 158′ of the piston 17. The conicalexternal surface 150 of the discrete centering member 165 has acircumferentially complete groove for a sealing element which is insealing engagement with the portion 158′ in the disengaged condition ofthe lockup clutch.

The means for anchoring the centering member 165 in the hub 11 includesan internal ring-shaped projection 166 which is received in a peripheralgroove 167 machined into or otherwise formed in the adjacent cylindricalportion of the hub 11. The elasticity of the centering member 165 issufficiently pronounced to enable a person or a machine or a tool toslip the member 165 onto the cylindrical portion of the hub 11 until theprojection 166 snaps into the groove 167. It is clear that theprojection can be provided on the hub 11 to enter a groove in theinternal surface of the centering member 165 and to thus locate thelatter in a desired axial position relative to the output element of thetorque converter including the structure of FIG. 16. It is also possibleto glue the centering member 165 to the hub 11.

FIGS. 17 and 18 illustrate a first embodiment of novel and improvedmeans for centering a torque converter (e.g., a torque converterembodying one or more previously described features of the presentinvention) on the rotary output member 3 of a prime mover (e.g., on acamshaft or crankshaft of an internal combustion engine in the powertrain of a motor vehicle). Accurate centering of a torque converter onthe rotary output member of a prime mover is necessary or at leasthighly advisable during initial mounting of the torque converter in thepower train.

Heretofore known centering or trueing means for the housing of a torqueconverter comprise a discrete part which is secured to the housing,e.g., to the driving section 4 of a housing 2 of the type shown in FIG.1. Such discrete part (shown in FIG. 1, as at 170) can constitute acomponent made of sheet metal, shaped in a deep drawing machine andprovided with a cupped (hollow) centrally located extension 171 which isbonded (e.g., by laser welding) or otherwise affixed to the drivingsection 4 of the housing 2. A laser welded seam is shown in FIG. 1 at172. Prior art proposals include several additional centering means allof which must be welded or otherwise bonded to the driving section ofthe housing of a torque converter.

A drawback of a discrete (separately produced) centering part (such as170) is that the connection of such part with the housing of a torqueconverter necessitates at least one secondary treatment subsequent tocompletion of the welding step (as at 172). Such welding and subsequentsecondary treatment involve extensive and expensive work in addition tothe initial cost of the centering part (170).

In accordance with a feature of the present invention, and as shown inFIGS. 17 and 18, the separately produced discrete centering part 170 canbe omitted by providing a much simpler (and hence less expensive)annular plate-like connector which serves as a means for securing thedriving section 4 to and for centering such driving section on therotary output member 3 of the prime mover. At the very least, the novelproposal to center the driving section 4 on the output member 3 involvesthe omission of at last one component (or of at least one detail on suchcomponent) and/or the elimination of at least one step or a sequence oftwo or even more steps. For example, the novel design of the means forcentering the driving section 4 on the output member 3 renders itpossible to eliminate a rather costly deep drawing operation (or toreplace a costly deep drawing operation with a much simpler and henceless expensive deep drawing operation) and a costly welding of the thusobtained part to the driving section 4. In addition, the aforementionedsimple annular plate-like (flat) connector (which replaces the discretecentering part 170 of FIG. 1) renders it possible to center the drivingsection 4 relative to an internal and/or external surface of the outputmember of a prime mover. For example, the connector can be centered onthat external surface of the output member 3 which serves to center thenormally flexible torque transmitting member 81. In other words, one andthe same seat of the output member 3 can serve to center severalcomponents including the normally or preferably flexible member 81 and aconnector which replaces the rather complex discrete centering part 170of FIG. 1.

Still another advantage of the just described novel centering method andcentering means is that the centering portion of the annular plate-likemember can be readily altered so as to conform to the seat of an outputmember of any one of a plurality of different prime movers (e.g., thecamshaft or the crankshaft of the internal combustion engine in thepower train of any one of numerous types of motor vehicles). Suchversatility of the novel centering means contributes significantly tothe ability of the torque converter to serve as a highly satisfactorytorque transmitting constituent in any one of numerous a types of powertrains.

It has been found that threaded fasteners can be utilized with advantageas a means for securing the annular plate-like centering member to theoutput member of a prime mover and/or to the driving section 4 and/or tothe torque transmitting member 81.

Also, in lieu of being affixed to the auxiliary mass or to the member81, the starter gear 90 can be readily secured to the novel centeringmember in an operation which can precede a centering of the torqueconverter housing on the output member of a prime mover (e.g., aninternal combustion engine).

The establishment of a reliable connection between the driving section 4and the novel annular plate-like centering member can involve a rathersimple welding and/or riveting operation and/or the utilization ofthreaded fasteners. The required secondary treatment is negligible, andthe necessary operations involving the making and installation of theimproved centering member are simple and short-lasting and can bereadily carried out by resorting to available machinery. For example,the annular centering member can be connected with the torquetransmitting member 81 in a simple and time-saving operation. Thisconstitutes a considerable simplification of the centering operationbecause the welding of a conventional centering part (170) to thedriving section 4 can create numerous problems as concerns adequatesealing of the internal space 14 of the housing 2 from the surroundingatmosphere, the possibility of deformation of the conical portion 21during the establishment of a welded connection (at 172 in FIG. 1)and/or others. In other words, the utilization of the novel centeringtechnique for the housing 2 is much less likely to exert an adverseinfluence upon the lockup clutch 15 and/or upon the aforedescribedcentering means for the piston 17 in the disengaged condition of thelockup clutch 15.

As shown in FIG. 17, the driving section 4 is a one-piece part whichincludes the conical portion 21. The preferably or normally flexibletorque transmitting member 81 is secured to the rotary output member 3by bolts 173 or analogous threaded fasteners. An annular plate-likecombined centering and connecting member or part 174 (which can have apolygonal outline as shown in FIG. 18) is affixed to the member 81 bybolts 175 or analogous threaded fasteners. The illustrated member 174has an outline corresponding to that of an equilateral triangle and itscorners have holes 176 (e.g., in the form of bores) for the shanks ofthe fasteners 175. In order to prevent the member 174 from lying flushagainst the torque transmitting member 81, the corners of the member 174are provided with recessed portions 177, 178. The recessed portions 178are deeper and smaller than the corresponding recessed portions 177, andthose parts of the member 174 which define the deeper recessed portions178 abut the member 81. The openings 176 are provided in those parts ofthe member 174 which define the deeper recessed portions 178. The deeperrecessed portions 178 serve as the portions which are connected orbonded to the flexible torque transmitting member 81 as shown in FIG.17.

The member 174 can be formed in a deep drawing machine and includes arelatively short tubular central portion 179 surrounded by a acylindrical internal centering surface 180 of the output member 3radially inwardly of the fasteners 173. The central portion 179 issurrounded by holes, openings or windows 181 (e.g., cutouts) of themember 174 which provide room for the introduction of the shanks of thethreaded fasteners 173 into tapped bores provided in a ring-shaped endportion 182 forming part of the output member 3 and surrounding thecylindrical centering internal surface 180.

A simple welded seam 183 (e.g., a laser welded seam) can serve as ameans for non-rotatably securing the member 174 to the driving section 4radially inwardly of the conical portion 21.

FIGS. 19 and 20 show a modification of the centering means for theannular member 174. The central portion 179 (FIGS. 17, 18) is omittedand a central opening 184 of the member 174 is centered externally on acylindrical portion 185 of the output member 3, the same as the torquetransmitting member 81.

FIG. 20 shows that the member 174 can be welded to the driving section 4at several arcuate locations 186. The welding can involve a so-calledMAG operation (thermod metal active gas welding) and takes place alongelongated arcuate slots 187 of the member 174. The centers of curvatureof the slots 187 and welded locations 186 are preferably disposed on thecommon axis of the output member 3 and the properly centered drivingsection 4. Furthermore, the slots 187 and the welded locations 186 arepreferably equidistant from each other as seen in the circumferentialdirection of the driving section 4 and its conical portion 21.

Referring to FIG. 21, there is shown a third centering arrangement forthe driving section 4, and more specifically an arrangement forcentering the driving section 4 on the hub 11. The manner of centeringthe section 4 on the output member 3 of a prime mover is or can be thesame as shown in FIG. 17. The driving section 4 includes a centrallylocated hollow centering projection 189 extending into a centeringrecess in the adjacent end face of the hub 11. Such centering recess issurrounded by a cylindrical internal centering surface 190 of the hub11. An optional bearing sleeve 188 is interposed between the peripheralsurface of the projection 189 and the internal surface 190.

FIG. 22 shows that the nuts 191 of FIGS. 17 and 19 (on the shanks of thefasteners 175) can be omitted if the member 174 is made of one piecewith nuts 191′ which can receive the shanks of the fasteners 175.

It is to be noted that the various novel features which are described inthis specification and are shown in FIGS. 1 to 22 can be used in anyproper combination with as well as independently of each other. Forexample, the feature(s) shown in any one of the FIGS. 2-22 can beutilized independently of the novel features of the torque converter 1of FIG. 1, the features of FIG. 10 or 11 can be used independently ofany and all (or some) other features, and so on.

The disclosures of all of the following U.S. Pat. Nos. are incorporatedherein by reference: 5,295,915, 5,667,448 and 5,711,730. The disclosureof the commonly owned U.S. Pat. application Ser. No. 08/649,065 (filedMay 16, 1996 by Dieter Otto et al.) is also incorporated herein byreference.

The disclosure of the U.S. Pat. No. 5,711,730 is of particular interestin connection with the utilization of a torque sensor having pluralplenum chambers in conjunction with a continuously variable transmission(CVT).

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic and specific aspects of our aboveoutlined contribution to the art of hydrokinetic torque converters and,therefore, such adaptations should and are intended to be comprehendedwithin the meaning and range of equivalence of the appended claims.

What is claimed is:
 1. A hydrokinetic torque converter comprising a housing rotatable about a predetermined axis and including a driving section; a rotary pump, a rotary turbine, and a stator disposed in said housing; an engageable and disengageable lockup clutch provided in said housing and spacedly surrounding said axis; a torque sensor disposed in said housing between said turbine and said driving section, as seen in the direction of said axis, and radially inwardly of said clutch; and means for centering said driving section of said housing on a rotary output element of a prime mover, including a substantially plate-like flexible torque transmitting member connectable with the output element of the prime mover, and an annular plate-like torque transmitting connector arranged to transmit torque between said flexible member and said driving section, wherein said connector includes a hub coaxial with said housing and received in a coaxial recess of said output element.
 2. The torque converter of claim 1, wherein said flexible member and said connector include radially outer portions remote from said predetermined axis, and means for securing said radially outer portions to each other.
 3. The torque converter or claim 2, wherein said means for securing comprises threaded fasteners.
 4. The torque converter of claim 1, wherein said connector has a polygonal outline and includes a plurality of corners offset in the direction of said predetermined axis toward said flexible torque transmitting member, said flexible torque transmitting member having recesses for said corners.
 5. The torque converter of claim 4, wherein said polygonal outline at least approximates the outline of an equilateral triangle.
 6. The torque converter of claim 1, wherein said connector includes portions bonded to said flexible torque transmitting member. 